The telephone is a major communication implement nowadays. Particularly, a wireless telephone can further enhance the space and range of telephone use.
Generally, the conventional telephone includes a handset that must be held by a user's hand. When the user's hand is occupied to do some other work, he/she always needs to clamp the handset between his/her shoulder and chin. This is inconvenient for the user. Furthermore, in a noisy situation, the user often shields his/her other ear from loudness with his/her free hand, and when the talk lasts a long time, the user feels exhausted.